Method of repairing liquid crystal display and apparatus using the method

Abstract

An apparatus for repairing a liquid crystal display comprises a common electrode, pixel electrodes facing the common electrode, and a liquid crystal sealed between the common and pixel electrodes. If the liquid crystal contains foreign matter which short-circuits the common and pixel electrodes to each other, a pixel electrode is irradiated with a laser beam such that at least a ring line region completely surrounding a portion touching the foreign matter is burnt away, whereby a region inside of the ring line region and a region outside of the ring line region are electrically insulated from each other.

What is claimed is: 
     
       1. A method of repairing a liquid crystal display which comprises a common electrode, pixel electrodes facing the common electrode, and a liquid crystal sealed between the common and pixel electrodes, and wherein the liquid crystal contains conductive foreign matter short-circuiting the common and pixel electrodes to each other, said method comprising the step of: irradiating a pixel electrode with a laser beam such that at least a ring-like region of said pixel electrode which corresponds to a ring line completely surrounding a portion touching the foreign matter is removed by the laser beam, whereby a region of said pixel electrode inside of the ring line region and a region of said pixel electrode outside of the ring line region are electrically insulated from each other.   
     
     
       2. An apparatus for repairing a liquid crystal display having a common electrode and a plurality of pixel electrodes, comprising: laser oscillating means for generating a laser beam;   alignment beam source means for outputting an alignment beam used for alignment of the laser beam generated from said laser oscillating means;   first optical means for defining a laser beam and the alignment beam in such a manner that the laser beam and the alignment beam have a cross section in the form of a closed loop, wherein said first optical means comprises a slit plate, which includes a glass plate, and a metal layer coated on the glass plate and having a ring slit corresponding to the closed loop;   XY carriage means on which the liquid crystal display is mounted and which is movable in an XY plane;   driving means for driving the liquid crystal display;   second optical means for focusing the laser beam and the alignment beam, the cross sections of which are in the form of a closed loop, on a predetermined portion of the liquid crystal display;   illuminating means for illuminating the liquid crystal display by directing light thereto through the second optical means;   image sensor means for image-picking up the liquid crystal display means through the second optical means, to generate an image signal; and   monitoring means for visualizing the image signal supplied from said image sensor means to allow detection of at least one of the pixel electrodes which is in contact with a foreign matter,   wherein a region of the pixel electrode which surrounds an electrode portion touching the foreign matter is removed by the laser beam.   
     
     
       3. An apparatus for repairing a liquid crystal display having a common electrode and a plurality of pixel electrodes, comprising: laser oscillating means for generating a laser beam;   alignment beam source means for outputting an alignment beam used for alignment of the laser beam generated from said laser oscillating means;   first optical means for defining the laser beam and the alignment beam in such a manner that the laser beam and the alignment beam have a cross section in the form of a closed loop, wherein said first optical means includes a plurality of slit plates which have different-diameter ring slits and are selectively employed.   XY carriage means on which the liquid crystal display is mounted and which is movable in an XY plane;   driving means for driving the liquid crystal display;   second optical means for focusing the laser beam and the alignment beam, the cross sections of which are in the form of a closed loop, on a predetermined portion of the liquid crystal display;   illuminating means for illuminating the liquid crystal display by directing light thereto through the second optical means;   image sensor means for image-picking up the liquid crystal display means through the second optical means, to generate an image signal; and   monitoring means for visualizing the image signal supplied from said image sensor means to allow detection of at least one of the pixel electrodes which is in contact with a foreign matter,   wherein a region of the pixel electrode which surrounds an electrode portion touching the foreign matter is removed by the laser beam.   
     
     
       4. An apparatus for repairing a liquid crystal display having a common electrode and a plurality of pixel electrodes, comprising: laser oscillating means for generating a laser beam;   alignment beam source means for outputting an alignment beam used for alignment of the laser beam generated from said laser oscillating means;   first optical means for defining the laser beam and the alignment beam in such a manner that the laser beam and the alignment beam have a cross section in the form of a closed loop, wherein said first optical means includes a slit plate having an arcuate slit, and means for rotating the slit plate by a predetermined angle;   XY carriage means on which the liquid crystal display is mounted and which is movable in an XY plane;   driving means for driving the liquid crystal display;   second optical means for focusing the laser beam and the alignment beam, the cross sections of which are in the form of a closed loop, on a predetermined portion of the liquid crystal display;   illuminating means for illuminating the liquid crystal display by directing light thereto through the second optical means;   image sensor means for image-picking up the liquid crystal display means through the second optical means, to generate an image signal; and   monitoring means for visualizing the image signal supplied from said image sensor means to allow detection of at least one of the pixel electrodes which is in contact with a foreign matter,   wherein a region of the pixel electrode which surrounds an electrode portion touching the foreign matter is removed by the laser beam.